I have been getting this as well more recently.. I have 68k in a 545i, so similar to you. Seems to happen going a speed between 35-50 mph. The engine kinda hesitates while going a constant speed.

Let us know what the outcome is!

 

Had the same exact problem with my 2004 545i with 82K miles. I thought it was the transmission shudder that others have described. I could recreate this behavior by manually shifting into 5th and holding the revs between 1,500 and 2,500. Every 2 to 3 seconds there was a lapse in power accompanied by stumble - enough to make your head tip forward and backward. I expected the mechatronics unit to be the culprit, again as others have described. The dealer determine rather quickly that the injectors were at fault. Apparently the momentary power loss caused the torque converter to unlock and relock instantly, resulting in the stumble. Although one or more injectors were not operating properly, no fault codes were being recorded by the ECU. New injectors solved the problem and the old injectors did not appear to be dirty or clogged. Good luck getting your issue resolved.

 

you should be able to meter the resistance across the injectors to make sure the windings are not shot, the readings should be within 10% of each other

 

Update - Dealer finally replicated the problem.

Diagnosis: need a new valve body. 5K. Thank goodness i got the extended warranty.

I am suprised it would need this kind of repair at 6oK miles.

 

What valve body?

 

sprint booster

 

I'm having the same problem, if you are underload but not foot flat to floor it it gives a slight jerk forward and does this 4-5 times but never noticed the revs climb at all must look next time.

I'm booking it in for next week for the dealer to look at and another list of problems

Hesitation
Squeaking Passenger Door/Window
CD Player Wont Eject CD's, also it wont play MP3's

 

Wow. How is it now?? Anymore info/details about the valve body would be appreciated.. so I have some ammo for the stealer

 

In a fight with third party warranty company now. They sent an "inspector" to BMW, and of course the problem wasn't occurring when they drove the vehicle (it only happens about 30% of the time.) They are denying the claim even though BMW has fault codes, engineer's report, etc documenting the failure.

Wll post more when I find anything out...

 

Damn, good luck!